It essentially allows you to make a part file behave like an assembly. It uses bodies instead of part files and sub assemblies to generate a bill of materials that is called a Cut-list. The cut list uses predefined fields, based upon the welding features you choose, or manually imputed into property fields: Structural member feature allows you to very quickly extrude many library sized cross sections or profiles. 2" square tubing, aluminum or steel, etc. After you have placed structural members and maybe a few gusset plates (use extrude feature but the "merge bodies" will be OFF by default since it is a weldment) you can also use the weld bead features to both graphically display the desired welds but also will generate some welding properties or parameters you have set up: Total weld weight, weld sizes material, etc. Think of it as simply a different work space or tool with different rules for final project communications.
